Application of Distributed Acoustic Sensing for Active Near-Surface Seismic Monitoring.

Area of Science:

• Geophysics
• Environmental Seismology
• Sensor Technology

Background:

• High-resolution near-surface imaging is crucial for geohazard studies and structural health monitoring.
• Traditional geophone surveys face limitations in complex geological settings.

Purpose of the Study:

• To evaluate Distributed Acoustic Sensing (DAS) fiber optic technology for active seismic surveys.
• To compare DAS performance against standard geophone surveys for monitoring critical infrastructure.

Main Methods:

• Conducted simultaneous active seismic surveys using DAS and geophones at the Rybnik Reservoir embankment.
• Employed a detailed data processing methodology for direct comparison of datasets.
• Utilized Multichannel Analysis of Surface Waves (MASW) for S-wave velocity analysis.

Main Results:

• DAS provided comparable data quality to geophones but with significantly higher spatial and temporal resolution.
• DAS demonstrated effectiveness in complex environments with high seismic noise and variable terrain.
• MASW using DAS data achieved a lower RMS error (3.26%) for S-wave velocity compared to geophones (6.2%).
• DAS data processing and interpretation were found to be easier.

Conclusions:

• DAS is a highly adaptable and effective technology for monitoring critical infrastructure and geohazards.
• Its superior resolution and ease of use in challenging conditions enhance geophysical assessments.
• Integrating DAS with traditional seismic methods offers a more comprehensive understanding of subsurface properties over time.